Aircraft typically have several access panels or doors that are removably attached to the exterior of the aircraft by quick-release fastener systems. A typical quick-release fastener system is comprised of fasteners that are mounted through holes in the access panel of the aircraft and receptacles for the fasteners that are secured to the interior structure of the aircraft that is covered by the access panel. When removably attaching the access panel to the aircraft, each fastener in a hole in the access panel is aligned with its associated receptacle on the interior structure on the aircraft. With a fastener aligned with its associated receptacle, rotating the fastener, for example a quarter turn or a half turn pulls the fastener down into its associated receptacle and attaches the access panel to the structure of the aircraft.
Each fastener of the quick-release fastener system has a length that is pulled into a receptacle when the fastener is releasably attached to the receptacle. When the access panel is removed from the aircraft, each fastener is free to move through its associated hole in the access panel. However, the extent to which the fastener can move through its associated hole in the access panel is limited by a head of the fastener at one end of the fastener, and a retaining ring attached to the fastener at an opposite end of the fastener. The head and retaining ring of the fastener are positioned on opposite sides of the access panel. The fastener is free to move through its associated hole in the access panel, but the head and the retaining ring at opposite ends of the fastener prevent the fastener from exiting the hole in the access panel.
The limited, free movement of the fasteners in their associated holes in an aircraft access panel presents a problem in access panels that are attached to the top and sides of an aircraft. When the access panel is removed from the top or side of an aircraft, the fasteners fall in odd positions due to gravity. This is not a problem on most of the access panels on the bottom of the aircraft as gravity pulls the fastener downward until the retaining ring engages against the interior surface of the access panel. Thus, gravity pulls fasteners on access panels on the bottom of the aircraft through their associated holes in the access panel and to their full-out positions relative to the access panel.
Substantially all aircraft use quick-release fasteners on access panels that cover frequently accessed areas of the aircraft. On some aircraft there could be ten or more access panels with hundreds of quick-release fasteners mounted on the access panels. Each of these fasteners has the potential to misalign with its associated fastener receptacle mounted on the structure of the aircraft, causing either damage to the fastener, damage to the access panel and/or damage to the sub-structure of the aircraft. Additionally, the misalignment of fasteners on their access panel presents a potential for a retaining ring of a fastener being knocked loose by contacting the sub-structure of the aircraft at an angle, with the retaining ring becoming a foreign object in an interior of the aircraft. Foreign object damage (FOD) is a real danger to aircraft as the foreign object can be sucked into engine intakes, or jam controls and cause electrical shorts if the loose retaining rings fall into the aircraft structure. All aircraft employing quick-release fasteners on their access panels are presented with the same problems with quick-release fastener removal and installation.